Certainly depends on where you live! Looks like you need ECO-off in AZ, but don't in ME or here in OR.

If you are in milder climes, ECO will cool the car below 77 degrees. The AC compressor has several power ranges and it won't run at full power below 77 if ECO is on. It's a rare day here that it won't maintain any reasonable temperature. We have it set to 73 or 74, any lower and it gets chilly.